[Biturbos4] Mervel Mystery Oil

John AudiFans at BackYardEngineering.com
Fri Dec 10 15:25:51 EST 2004

Keman wrote:
> Let me be the first to say not to even put it into the trunk in the bag
> from the store which you purchased it from.
> I've certainly worked on cars enough over the years to be familiar with
> crazy attempts to get more detergents into oil, ie: using ATF instead of
> oil to break down all the varnish etc (Done that!) ... but at this point
> what I've seen from the dudes at Mobil or Redline or Amsoil, there is no
> need and at best it might cause problems.
> Just my .02 ... if you want to spend more money on oil, use redline.
> As far as the viscosity... since I know this topic will come up again,
> 5W-30 in the winter, 10W-30 in the summer .. pure synthetic.
> 15W-50 under very hard use / high heat conditions in any season.
> I know Audi recommends 0W-30, I know some people put in 0W-40 and swear by
> it. Myself, I've determined that is only for mileage. Not longevity.
> Over the last 6 years the engine bearing tolorances have not changed one
> bit, yet a late 90's 1.8T owners manual says in big bolt print "Use 5W-30
> if all other grades are not available and do not drive the engine at high
> speeds on this oil" ... they recommend 15W-50 for all temps down to 0
> degrees F. Flip forward a couple of years and poof.. wow.. what's this.
> 0W-30. No warning about using 5W-30 at all.

As with any "snake oil", you have to ask what you are trying to fix... ;-) 40 
years ago when detergent oils and fuel additives were rare, Marvel Mystery oil 
probably made sense. Today, if you are using qulity oil and gasolines, they 
probably have plenty of cleaning additives. I use Marvel Mystery oil for air 
tool lubricant and have on occasion used it in the fuel tank to supplement oil 
mix on a *rotary* engine. I would never get it anywhere near the fuel or oil 
system of my Audi.

I agree with Keman on the alarming trend in oil viscosity. For example a 1981 
SAE oil chart listed the upper operating limit of 5W-30 at ~35° F and 10W-30 at 
less than 90° F. 0W anything was unheard of.

Our '01 A6 came with 0W-30 factory fill. What exactly is 0W? Does that mean at 
cold start it's like having no oil at all? 8-0 Personally I run 10W-30 Mobil 1 
(instead of dino oil), partly because of Audi's 10K mile oil change interval and 
that Mobil1 meets ACEA (Redline does not). Fortunately our warranty services 
have been coming up on time, not milage...

Just to add to the confusion, :-/  from the Mobil1 site: "10W-30 5° F to 59° F", 
but when you look at the spec, it says: "Mobil 1 10W-30 is recommended for all 
types of modern vehicles, including high-performance turbo-charged...exceeding 
the needs of 2001 & newer gasoline cars". Who knows anymore... IMHO, modern oil 
specs are driven more by the politics of things like CAFE specs, the factories 
could care less if your engine goes more miles than the warranty.


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